A vehicle transmission device provides power transmission and speed switch for the operation demands of the vehicle to advance. The transmission device includes a driving shaft or an input shaft connected with a power source. The input shaft is provided with an input gear set and spring-like members disposed inside the input gear set. An output gear set is provided to mesh with the input gear set. A transmission control mechanism is disposed on the input shaft for the input gear set to transmit a power to the output gear set and an output shaft to output the power to drive the vehicle. The present invention can enhance the power, torsion and speed of the vehicle.